GB370707A - A connection system for multi-grid valves - Google Patents

Abstract

370,707. Valve amplifying and detecting circuits. RADIO AKT.-GES. D. S. LOEWE, 10, Wiesenweg, Steglitz, and KAPTEYN, P., 5, Schwalbacherstrasse, Friedenau, both in Berlin. May 21, 1931, No. 14969. Convention date, May 21, 1930. [Class 40 (v).] A screen-grid valve with resistance coupling to a following valve employs an anode resistance 5 greater than a megohm, and has a high resistance 26 shunted by a condenser 27 in its screen circuit. The screen connection to the battery 28 may be taken at the same point as the plate connection, or at a different point. A further grid 13 connected to the cathode may be employed. The purpose is to make the operation of the amplifier less critical when the control grid bias is varied, as when the valve is switched over from the detection of wireless signals to the amplification of gramophone reproduction. The circuit gives also an automatic regulation of the amplification, large input resulting in increasing screen-grid current and consequently diminished screen voltage. The condenser 27 may be varied to adjust the amplification of the valve stage. The circuit may be employed in multiple-stage valves. Specification 338,613, [Class 40 (v), Wireless signalling &c.], is referred to.